str1 = 'qwertyuiop'
# 求字符串长度
print(len(str1))

print('===========')
# 将字符串转为ASCII值
print(ord('a'))
print(ord('A'))
print(ord('0'))

print('===========')
# 将ASCII值转为字符串
print(chr(97))
print(chr(65))
print(chr(48))

print('===========')
x = 4
print(eval("3*x"))
